Servlet中的this.getServletContext().getRealPath()

今天遇到了this.getServletContext().getRealPath()；写了个Servlet看看怎么用，直接贴代码：

package com.yf.Servlet.Demo;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

@WebServlet("/ReadFileServlet")
public class ReadFileServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        response.setCharacterEncoding("utf-8");
        request.setCharacterEncoding("utf-8");
        PrintWriter printWriter = response.getWriter();
        String fileName = "WEB-INF/web.xml";//文件相对路径
        //this.getServletContext().getRealPath("/")的值为D:\Servlet\target\Servlet\
        //所以this.getServletContext().getRealPath(fileName);的值为D:\Servlet\target\Servlet\WEB-INF/web.xml
        String filePath = this.getServletContext().getRealPath(fileName);//文件绝对路径
        printWriter.println(filePath);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

可以看出当我们用this.getServletContext().getRealPath("/")时得到的路径是我们项目的绝对路径D:\Servlet\target\Servlet\ 这也就是项目WEB-INF的上一级路径。当我们需要定位到WEB-INF
下面路径时只需要在this.getServletContext().getRealPath("/")中添加相对路径即可